SYSTEMATIC REVISION OF ALLOCHROA ANCEY, 1887 (PULMONATA, ELLOBIIDAE),WITH AN ACCOUNT OF THE ANATOMY OF ALLOCHROA LAYARDI (ADAMS,H. AND ADAMS,A., 1855) AND THE DESCRIPTION OF 2 NEW SPECIES

Of the nominal species of Allochroa Ancey, 1887 described to date, onl y two are recognized: A. bronnii (Philippi, 1846), endemic to the Hawa iian Islands, and A. layardi (H. & A. Adams, 1855), distributed throug hout the Indo-Pacific. Examination of the USNM collection revealed two additional species, A, nana Martins, n. sp. and A. tenuis Martins, n. sp., herein described. The anatomy of A, layardi is described and ser ves as the basis for determining the relationships of this genus withi n the Ellobiidae. Allochroa has a monaulic, entirely glandular pallial gonoduct and a wide visceral nerve ring with a long right parieto-vis ceral connective, confirming placement in the Pythiinae. Its close rel ationship to the Mediterranean and Eastern North Atlantic genus Ovatel la Bivona, 1832 is indicated by similar apertural dentition, protoconc h morphology of A. tenuis, and by the internal structure of the penial complex, where the penis appears as the development of one of the pil asters.